The present invention relates to a device for transmitting radiophonic signals in secondary radar equipment. More precisely, such radar equipment is equipped with an interrogation device known under the abbreviation IFF and therefore comprises two antennae, one directional, the other omnidirectional or having in its radiation diagram zones with zero or very low gain.
These two antennae are supplied alternately according to a predetermined sequence for obtaining, on reception, echoes from the same target corresponding to a law of amplitude thus predetermined which enables them to be distinctly separated from spurious echoes. Moreover, interrogated targets, generally airplanes, are fitted with transponders which, receiving the impulses emitted by the interrogation device, emit in response towards this radar a coded signal allowing it to be identified. At this stage of the information about the target the operator of the radar generally enters into direct radiophonic communication with the interrogated target.
In the prior art, the antennae used for these radiophonic connections are of the whip or sword type and are disposed in the immediate vicinity of the antennae of the interrogation device especially in the cases where the equipment is carried for example by a truck or a tank. These antennae present several drawbacks:
their matching is very difficult because of the vehicle on which they are generally fixed; PA1 their radiation diagrams may present angular zones with very low gain because of the presence of the antennae of the interrogation device forming an obstacle which disturbs the proper operation of the radiophonic antennae.